Traffic grooming technique for elastic optical networks: A survey

The concept of elasticity has been proposed in the design of next generation optical networks in tackling the problem of efficient utilization of network resources and increasing traffic demands. The elasticity property allows the capacity of lightpaths to best fit the user demands. Even with the elasticity property, there is still a possibility to further improve the resource usage in terms of spectrum or transmitter savings with some techniques developed by research community. The reasoning behind this survey was to emphasize one of them, namely traffic grooming technique, considering the grooming capability at the optical level. Such grooming technique allows the establishment of optical tunnels carrying a several connections in a contiguous block of spectrum without inserting guard bands in between, therefore minimizing the spectrum usage or the number of transmitters. A number of algorithms have been proposed recently in solving this problem including static and dynamic traffic scenario. The objective of the paper is to review, classify and discuss a range of these algorithms in elastic optical networks. The outcomes are expressed as a summar comparison of available algorithms with their main features and objectives. To the best of our knowledge, it is the foremost paper that provides a survey on optical level grooming for elastic optical networks.